This invention relates generally to hydraulic brakes, and more particularly concerns a hydraulic brake having provision for accommodating a service brake actuator in combination with a primary brake actuator.
In hydraulically driven power trains, hydraulic brakes are commonly used to control the rotating speed of shafts and associated parts. For example, such power trains can include a hydraulic motor which turns a shaft connected to a speed reducer. A hydraulic brake, interposed between the motor and the speed reducer, can be used to control shaft speed and to quickly halt shaft rotation when hydraulic power train operation is no longer desired.
In such applications, these brakes can provide a powerful motion-retarding force, are relatively compact, and can be provided at relatively low cost.
In many applications, it is important that the brake be of the failsafe variety, i.e., that the brake be designed so that a braking force is applied should a failure occur in the hydraulic system. One such brake which has met with considerable commercial success is that disclosed and claimed in U.S. Pat. No. 3,863,038.
It is the general object of the present invention to provide a hydraulic failsafe brake which accommodates and utilizes a service brake actuator as well as a primary braking system actuator. A related object is to provide such a brake which permits application or energization of the service brake without effectively disturbing other portion of the braking system and the hydraulic pressures present therein.
Another object is to provide a hydraulic brake of the failsafe variety in which a second fluid pressure system can be provided for controlling action of the primary fluid system and the consequent braking action. A related object is to provide such a secondary braking system in a design which maintains the failsafe character of the brake.
Yet another object of the invention is to provide a hydraulic brake of the type described which permits braking action to be smoothly and precisely applied.
Yet another object is to provide such a brake which is compact in size, yet reliable and rugged in design, and which can be offered at an attractive commercial cost.
Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. Throughout the drawings, like reference numerals refer to like parts.